1557.73 
Gr-5 
c .  3 


STATE  OF  ILLINOIS 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 

A.  M.  SHELTON.  Direc  or 

DIVISION  OF  THE 

STATE  GEOLOGICAL  SURVEY 

M.  M.  LEIGHTON.  Chief 

REPORT  OF  INVESTIGATIONS-NO.  5 

STRUCTURE  OF  HERRIN  (NO.  6)  COAL 
SEAM  NEAR  DUQUOIN 

BY 

D.  J.  FISHER 


ILLII^DIS  DOCUMENT 

JAN  1  3  1968 


ILLl  ms  STATE  LIBRAR 


PRINTED  BY  AUTHORITY  OF  THE  STATE  OF  ILLINOIS 


URBANA.  ILLINOIS 
1925 


£3- 


STATE  OF  ILLINOIS 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 

A.  M.  SHELTON,  Dirac  or 

DIVISION  OF  THE 

STATE  GEOLOGICAL  SURVEY 

M.  M.  LEIGHTON.  Chiaf 


REPORT  OF  INVESTIGATIONS-NO.  5 


STRUCTURE  OF  HERRIN  (NO.  6)  COAL 
SEAM  NEAR  DUQUOIN 


BY 

D.  J.  FISHER 


PRINTED  BY  AUTHORITY  OF  THE  STATE  OF  ILLINOIS 


URBANA,  ILLINOIS 
1925 


ILLINOIS  STATE  LIBRARY 


STATE  OF  ILLINOIS 

DEPARTMENT  OF  REGISTRATION  AND  EDUCATION 

DIVISION  OF  THE 

STATE  Gl^OLOGlCAJ.  SUR\  EY 

M.  M.  LEIGHTON,  Chief 


Goniniittee  of  the  Board  f)f  Natural  Besoure(*s 

and  Gonsei'valion 


A.  M.  Sheltox.  Chairman 

Director  of  Registration  and  Education 


Kexdhtc  C.  Babcock 

Representing  the  President  of  the  Uni 
versity  of  Illinois 

Edsox  S.  Bastix 
Geologist 


^  TRAPES  tegcorNaL » 


SCHNEPP  &  Barnes,  Printers 
Springfield,  III. 

1925 


32712—1500 


7-  7  ? 


/  ‘ 


STRLCTUKK  OF  HI^.RRIX  (NO.  (>)  COAL  SEAM 

NEAR  J)UQL()IN 


By  D.  J.  Fisher 

OUTLINE 

PAGi': 

Introduction  . 7 

Location  .  7 

Object  of  report .  7 

Methods  of  study .  7 

Acknowledgments  . 7 

Previous  work  and  bibliography .  8 

Stratigraphy .  8 

General  statement  .  8 

Origin  of  strata .  8 

Formation  of  shale  and  limestone .  9 

Formation  of  coal .  9 

Description  of  the  rocks .  9 

General  statement  .  9 

Herrin  (No.  6)  coal .  10 

Strata  below  Herrin  coal .  11 

Beds  between  Herrin  and  Harrisburg  coals .  11 

Harrisburg  (No.  5)  coal .  12 

Strata  above  Herrin  coal .  15 

The  “cap-rock”  limestone .  15 

Strata  between  the  “cap-rock”  limestone  and  the  Herrin  coal  15 

Limits  of  the  area  underlain  by  the  Herrin  coal .  17 

Accuracy  of  the  boundary  line .  17 

Absence  of  coal  in  region .  18 

Area  of  possible  non-deposition .  18 

Areas  of  subsequent  erosion .  18 

Structure  .  18 

Structural  features  developed  before  or  during  consolidation .  18 

Splits .  18 

General  statement  .  18 

The  mapping  of  split  areas .  19 

Detailed  descriptions  of  areas  underlain  by  split  coal .  19 

Majestic  mine  .  19 

Mulkeytown  area  .  21 

Hallidayboro-Bush  area  .  21 

Origin  .  21 

Structural  features  developed  after  consolidation .  22 

General  considerations  .  22 

Structure  contours  .  23 

Accuracy  of  the  structure  contours .  24 

Warping  .  24 

Duquoin  monoclinal  flexure .  24 

Faulting .  25 

General  character  of  the  faults .  25 

Systems  of  faulting . 25 


O 

O 


OUTLINE— Concluded 


Description  of  the  faults . 

Faults  near  Weaver . 

Faults  near  Royalton . 

Faults  near  Hallidayboro . 

Faults  near  Dowell . 

Faults  east  of  Duquoin . 

Practical  economic  aspects . 

Value  of  the  structure  contour  map,  Plate  I.  .  .  . 
Effects  of  faulting  on  mining  methods  at  Dowell 
Importance  of  drilling . ’ . . 


PAGE 
,  26 
26 
,  27 
28 
,  29 

31 
,  32 

32 

33 
.  33 


ILLUSTRATIONS 

PLATE  PAGE 

I.  Map  of  the  Duquoin  area  showing  structure  of  the  Herrin  coal 

seam  . Pocket 

II.  Structure  map  of  the  Kathleen  mine  at  Dowell . Pocket 

FIGURE 


1.  Division  of  the  State  into  districts,  and  area  covered  in  this  report  6 

2.  The  Herrin  coal  in  its  unusual  thickness  of  about  13  feet  near 

Christopher .  19 

3.  Photograph  of  the  “blue-band”  in  the  Herrin  coal .  11 

4.  Generalized  columnar  section  showing  strata  above  and  below  the 

Herrin  coal  .  12 

5.  Map  of  the  Duquoin  area  showing  drill  holes  which  reach  the 

level  of  the  Harrisburg  (No.  5)  coal  seam .  14 

6.  Convergence  map  showing  interval  between  the  “cap-rock”  lime¬ 

stone  and  the  Herrin  coal  at  Dowell .  16 

7.  Diagrammatic  cross-section  of  split  in  the  Majestic  mine .  19 

8.  Detail  of  north  side  of  split.  ^lajestic  mine .  20 

9.  Surface  of  the  Herrin  coal  as  it  would  appear  if  all  the  overlying 

material  were  removed .  23 

10.  Cross-section  of  main  fault  in  No.  2  Inline  at  Bush .  27 

11.  Cross-section  of  fault  in  the  main  west  entry  of  the  mine  at 

Hallidayboro  .  28 

12.  Cross-section  of  fault  in  the  back  east  entry  of  the  mine  at 

Hallidayboro  .  29 

13.  Profile  of  faulted  area  in  the  Kathleen  mine .  39 

14.  Detailed  sketch  of  a  fault  in  the  Kathleen  mine .  31 

15.  Cross-section  of  a  fault  in  the  Kathleen  mine .  32 

TABLES 


1.  Summarized  data  regarding  the  thickness  of  several  limestones 

and  the  intervals  between  them  and  the  Herrin  coal .  15 


Digitized  by  the  Internet  Archive 
in  2018  with  funding  from 
University  of  Illinois  Urbana-Champaign 


https://archive.org/details/structureofherriOOfish 


() 


STRUCTURE  OF  IIERRIX  COAL  NEAR  DUQUOIX 


JO  DAVIESS 


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UNION  [JOHNSON 


Fig.  1.  Index  map  of  the  State  showing  the  various 
coal  districts  and  the  area  covered  hy  this  report  outlined 
in  a  heavy  black  line. 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUOUOIN 


INTRODUCTION 


Location 

The  area  covered  1)y  this  report  lies  in  the  southern  part  of  Illi¬ 
nois  and  includes  portions  of  Franklin,  Jackson,  Jefferson,  Perry, 
\\  ashington,  and  Wdlliaiuson  counties.  It  is  rectangular,  about  2<S  by 
U  miles,  and  contains  4Gb  s([uare  miles.  Figure  1  indicates  its  location 
and  extent.  It  comprises  portions  of  coal  districts  If,  \  l.  and  ATI. 

Object  of  Report 

The  purpose  of  this  report  is  to  set  forth  the  results  of  a  geologic 
study  of  the  Herrin  (No.  G)  coal  seam.  These  include  the  lay  or 
amount  of  dip  of  the  coal  bed,  and  the  faults,  splits,  and  other  features 
which  interru]3t  its  continuity.  The  physical  characteristics  and  modes 
of  origin  of  the  coal  and  its  enclosing  beds  are  also  briefly  treated. 
Emphasis  is  placed  upon  the  economic  aspects  of  the  geologic  features. 

?^Ietiiods  of  Study 

About  six  weeks  were  spent  in  field  work  during  the  summer  of 
1944,  and  44  of  the  29  shipping  mines  shown  on  Plate  I  were  visited. 
L^nderground  work  was  done  in  mines  indicated  on  the  map  b}^  num¬ 
bers  L  8,  14,  13,  15,  19,  and  45.  The  results  given  herein  are  based 
up'on  observations  in  the  mines  by  the  writer,  upon  detailed  struh^  of 
available  mine  maps  and  logs  of  drill  holes,  and  upon  study  of  geo¬ 
logic  work  previously  completed  in  this  area.  It  was  rare  to  get  uu- 
condicting  data  on  the  abandoned  mines,  as  most  of  this  sort  of  ma¬ 
terial  was  obtained  from  the  older  residents.  The  locations  of  some 
mines  are  probably  more  or  less  inaccurate  but  where  maps  or  accu¬ 
rate  descriptions  were  available,  the  data  so  obtained  were  incorporated 
in  the  report,  ddie  locations  of  abandoned  mines  that  came  to  the 
attention  of  the  writer  are  shown  on  Plate  I,  but  undoubtedly  others 
existed.  No  attempt  is  made  to  show  the  areas  of  the  old  workings, 
though  generally  they  were  small,  few  exceeding  40  acres  in  extent. 

A  C  K  N  o  W'LED  G  :\I  E  N  T  .S 

The  advice  and  assistance,  both  in  the  office  and  in  the  field,  of 
Dr.  H.  E.  Culver,  in  charge  of  coal  studies  for  the  Illinois  Geological 
Survey,  are  gratefully  acknowledged.  iMost  of  the  mine  superinten¬ 
dents  or  engineers  cooperated  in  this  study  and  contributed  much  to 
the  value  of  this  report.  To  them  especial  acknowledgment  is  made. 
Idle  extraordinary  generosity  of  the  officials  of  the  Lmion  Colliery 


8 


STRUCTURE  OF  IIERRIK  COAL  NEAR  DUOUOIN 


Company  deserves  specific  mention.  The  writer  feels  under  great 
obligation  to  Dr.  AI.  AI.  Leighton,  Chief,  and  to  Aliss  H.  P.  C.  Christen¬ 
sen,  of  the  Illinois  Geological  Survey,  for  aid  in  revising  the  manu¬ 
script. 

Previous  Work  and  Bibliography 

Although  the  area  covered  by  the  report  lies  in  parts  of  three 
coal  districts,  it  is  nevertheless  a  structural  unit,  and  as  such  deserves 
a  specific  rcjiurt.  Previous  workers  have  been  handicapped  somewhat 
by  artificial  boundaries,  so  that  a  detailed  study  of  the  whole  structure 
was  impossible.  The  more  important  publications  describing  geologic 
work  previously  done  in  the  area  are  as  follows : 

1.  Udden,  J.  A.,  Coal  Deposits  near  Duquoin;  Ill.  State  Geol.  Survey  Bull. 

14,  pp.  254-262,  1909.  This  paper  gives  a  short  summary  of  earlier 
work  in  the  area. 

2.  Shaw,  E.  W.  and  Savage,  T.  E.,  U.  S.  Geol.  Survey  Geol.  Atlas,  Murphys- 

boro-Herrin  folio  (No.  185),  1912. 

3.  Kay,  F.  H.,  Coal  Resources  of  District  VII:  Ill.  Mining  Investigations 

Bull.  11,  1915. 

4.  Cady,  G.  H.,  Coal  Resources  of  District  VI:  Ill.  Mining  Investigations 

Bull.  15,  1916. 

5.  Cady,  G.  H.,  Coal  Resources  of  District  II:  Ill.  Mining  Investigations 

Bull.  16,  1917. 

6.  Shaw,  E.  W.,  U.  S.  Geol.  Survey  Geol.  Atlas,  Carlyle-Centralia  folio 

(No.  216),  1923.  Centralia  is  located  about  20  miles  north  of  the  area 
described  in  this  paper. 

STRATIGRAPHY 
General  Statement 

The  consolidated  rocks  in  the  area  belong  to  the  Pennsylvanian 
system,  which  in  Illinois  is  divided  into  the  Pottsville,  Carbondale, 
and  the  (youngest  or  uppermost)  McLeansboro.  These  formations 
have  been  jireviously  studied  and  described,  and  only  pertinent  facts 
will  be  reviewed  here. 


Origin  of  Strata 

During  the  Pennsylvanian  period,  the  surface  of  the  southern 
two-thirds  of  Illinois  was  essentially  flat  and  probably  near  sea  level 
most  of  the  time.  It  was  subject  to  slow  fluctuations;  at  times  it  was 
slightly  above  sea  level,  and  at  other  times  sea  water  covered  much 
or  all  of  the  area. 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIN 


:) 


FORMATION  OF  SHALE  AND  LIMESTONE 

During  part  of  the  time  that  the  sea  covered  the  district,  muds 
formed  from  the  erosion  of  adjacent  low-lying  or  distant  high  land 
areas  were  carried  into  the  sea  l)y  streams.  These  muds,  deposited 
on  the  bottom  of  the  sea,  were  buried  by  other  sediments,  and  even¬ 
tually  set  into  shales.  At  other  times,  little  or  no  clastic  material  was 
brought  into  the  sea  and  the  only  deposit  was  calcium  carbonate, 
formed  by  precijiitation  of  this  sulistance  which  was  dissolved  in  the 
sea  water  and  by  the  secretions  of  animals  and  plants  living  in  the  sea. 
This  de])osit,  when  cemented  into  solid  rock,  formed  the  limestone. 
Most  of  the  shale  of  the  area  is  calcareous,  indicating  that  calcium 
carbonate  was  being  deposited  more  or  less  continuously. 

FORMATION  OF  COAL 

During  much  of  the  time  that  the  area  was  above  but  near  sea- 
level.  it  was  covered  by  rather  watery  swamps  out  of  which  grew  a 
luxuriant  vegetation,  somewhat  similar  to  the  present  cypress  swamps 
of  some  localities  in  the  southern  states.  Trees  and  other  types  of 
vegetation  lived,  grew  old,  and  on  dying  fell  into  the  swampy  waters 
that  had  covered  the  soil  from  which  they  grew.  Falling  underneath 
water,  the  vegetable  material  did  not  rot  as  it  does  in  most  of  our 
present  forests,  but  suffered  a  sjiecial  type  of  partial  decay  that  ])er- 
mitted  the  removal  of  but  little  of  the  carbon  content  of  the  wood  as 
carbon  dioxide  gas.  New  vegetation  grew  on  the  old.  In  some  such 
manner,  the  jirocess  continuing  many  thousands  of  years,  many  feet 
of  this  partially  decomposed,  carbonaceous,  peaty  material  accumu¬ 
lated.  It  is  conservatively  estimated  that  about  250  feet  of  material 
such  as  is  found  near  the  surface  of  a  coal  swamp  are  needed  to  even¬ 
tually  form  an  (S-foot  coal  seam.  This  does  not  mean  that  at  any  one 
time  there  were  250  feet  of  water-buried  vegetable  matter  in  the  area, 
as  under  such  conditions  the  lower  part  would  be  subjected  to  a  pres¬ 
sure  equal  to  the  weight  of  all  the  overlying  material,  which  would 
conqiress  the  plant  tissues,  and  squeeze  out  much  of  the  water.  In 
fact,  the  lower  part  was  probably  compressed  to  approximately  one- 
tenth  of  its  original  thickness,  even  before  the  peaty  matter  was  buried 
by  other  sediments. 

Description  of  the  Rocks 

GENERAL  STATEMENT 

In  the  discussion  of  the  Pennsylvanian  strata  the  usual  order  of 
description  of  formations  from  oldest  to  youngest  is  not  followed. 


]()  STRUCTURE  OF  IIERRIX  COAL  NEAR  DL’OUOIX 

Because  of  the  importance  of  the  Herrin  coal  in  this  area  that  coal 
is  described  hrst.  Then  the  formations  below  Herrin  coal  in  descend¬ 
ing  order  are  taken  up,  after  which  the  formations  above  the  coal  from 
the  “cap-rock”  limestone  down  to  the  Herrin  coal  are  described. 


Fig.  2. — The  Herrin  coal  in  its  unusual  thickness  of  about  13  feet  near 
Christopher.  (Courtesy  of  Purity  Coal  Co.) 

HERRIX  (xo.  G)  COAL 

The  Herrin  coal  (fig.  2)  lies  at  the  top  of  the  Carbondale  series 
of  beds.  In  the  Duquoin  area,  east  of  the  main  line  of  the  Illinois 
Central  Railroad  this  seam  averages  8  to  9  feet  in  thickness,  but  west 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIN 


of  this  railroad  it  probably  does  not  average  more  than  G  feet.  It  is 
characterized  by  a  dark-colored,  clayey  parting,  called  the  “blue  band” 
(fig.  3)  which  averages  about  2  inches  in  thickness  and  generally  lies 
1  to  2  feet  above  its  base.  Other  variations  from  pure  coal  are  read¬ 
ily  noted,  but  lack  the  great  persistence  and  regularity  of  the  “blue- 
band”.  The  uniformity  in  thickness  of  this  coal  bed  and  the  contin¬ 
uity  of  the  “hlue-band”  over  such  a  relatively  broad  area  are  remark¬ 
able  features. 


Fig.  3. — Photograph  of  the  “blue  band,”  a  characteristic  feature  in  the 
lower  part  of  the  Herrin  coal. 

STRATA  BELOW  HERRIN  COAL 
BEDS  BETWEEN  HERRIN  AND  HARRISBURG  COAI.S 

Below  the  Herrin  coal  (fig.  d)  is  found  a  gray  clay  known  as  “fire 
clay”,  in  places  as  much  as  10  feet  thick.  The  thickness  is  greatly  var¬ 
iable.  Locally  the  clay  is  absent.  This  clay  or  in  its  absence,  the  coal,  is 
underlain  by  a  light  gray,  very  fine-grained  limestone,  averaging  about 
10  feet  in  thickness.  It  contains  marine  fossils,  among  which  are 
petrified  tests  (“skeletons”  or  “shells”)  of  simple  animals.  These 
resemble  a  fairly  thick  grain  of  wheat,  have  a  spiral  cross-section,  and 
belong  to  the  FiisiiUna  family.  Below  this  limestone,  gray  shale  is  the 
dominant  sediment  until  the  next  coal  bed  is  reached.  This,  the 
Harrisburg  or  No.  5  coal,  lies  about  30  to  43  feet  below  the  Herrin 
seam,  although  intervals  varying  from  15  to  50  feet  have  been  reported. 


12 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUOUOIN 


HARRISBURG  ( NO,  5)  COAL 

Inasmuch  as  it  was  considered  that  a  study  of  the  Harrisburg 
coal  bed  would  add  little  or  nothing  to  the  problem  in  hand,  no  effort 


r  150 


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Limestone,  medium 
gray,  crystalline. 

Shale,  gray. 

Coal. 

Shale,  gray. 

(Little  coal  and  "fire  clay") 


Limestone,  compact, 
light  gray. 


Limestone,  cap  rock, 
fusulina,  medium 
grained,  dark  gray. 

Shale,  blaok  fissile. 


Shale,  gray,  (sandy) 


Herrin  (No.  6)  coal. 

"blue  band" 

"Fire  clay" 

Limestone,  compact, 
light  gray 


Shale,  gray,  (sandy) 


Shale,  black  fissile 
No.  5  coal. 


Fig.  4.  Generalized  columnar  section  showing  the 
strata  above  and  below  the  Herrin  (No.  6)  coal.  The 
thicknesses  shown  represent  the  average  for  the 
thickly  drilled  area  near  Dowell. 


was  made  to  gather  data  on  this  seam.  However,  because  of  the  in¬ 
terest  shown  by  certain  operators  in  the  Duquoin  area,  the  following 
statement  is  included. 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIN 


1  -> 

So  far  as  it  is  known,  only  one  mine  in  the  area  is  removing’  any 
coal  from  the  Harrishurg  seam.  A  small  local  mine  operated  hy  the 
Parrish  Coal  Company  of  De  Soto,  and  located  one  mile  northwest 
of  De  Soto  in  the  SWk  N\V.  ^  sec.  17,  T.  8  S.,  R.  1  \\  .,  is  reported 
to  be  w^orking  this  seam.  The  section  shown  in  the  shaft  is  as  follows : 

d'hickness 

Feet 

Clay  .  20 

Limestone  .  2 

Shale  .  20 

Limestone,  dark  gray .  2-d 

Shale,  black  fissile .  0-1^ 

Coal  (No.  5)  .  d-d 

The  clay  at  the  to])  of  this  section  is  ])resumal)ly  of  glacial  origin. 
Judging  from  the  above  stratigraphic  section  the  Harrisburg  seam  was 
l)robably  about  40  feet  below  the  base  of  the  Herrin  coal,  before  the 
latter  was  removed  hy  erosion. 

In  the  mine  of  the  Jackson  Coal  Company  at  Hallidayboro,  just 
west  of  the  shaft  and  east  of  the  main  fault,  an  entry  which  is  now 
fallen  in  w^as  cut  sloping  to  the  northwest.  It  is  reported  that  the 
Harrisburg  coal  was  found  about  50  feet  below  the  Herrin  seam.  No 
data  as  to  the  thickness  or  character  of  the  Harrisburg  coal  at  this 
locality  were  available. 

Faulting  or  movements  in  the  rocks  involving  breakage  and  actual 
displacement  of  the  strata  has  in  a  few  cases  brought  the  Harrisburg 
coal  up,  so  that  it  is  at  or  near  the  same  level  as  the  Herrin  coal.  This 
affords  the  possibility  of  mining  both  beds  from  the  same  mine  level. 
It  is  reported  that  in  the  south  part  of  the  Kathleen  mine  at  Dowell, 
the  easternmost  fault  in  NE.  sec.  8  (PI.  H  )  with  upthrow  on  the 
east  side  has  brought  the  Harrisburg  coal  up,  so  that  it  appears  in  the 
face  of  entries  9-10  E.  off  the  main  south  entry  cut  in  the  Herrin  coal. 

Eigure  5  is  a  sketch  map  of  the  Duquoin  area  showing  the  loca¬ 
tions  of  the  drill  holes  which  reach  the  level  of  the  Harrisburg  coal. 
The  holes  in  which  this  scam  is  absent  or  not  thicker  than  2  feet  are 
indicated  by  a  different  symbol  from  those  in  which  it  is  at  least 
feet  thick.  In  most  holes  the  thickness  is  4  to  5  feet.  One  loef  of 
a  hole  near  St.  John  shows  0  feet  ;  one  near  Waltonville,  7  feet.  Data 
from  the  logs  of  about  50  holes  in  the  area  show  the  average  thickness 
of  the  Harrisburg  coal  to  be  4J4  feet  and  the  average  depth  below 
the  Herrin  seam  to  be  35 feet. 


crtooH  c«'jh  j>o-i 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIN 


1  } 


R.2W.  R.  1W.  R.  IE. 


Fic.  5.  Map  of  the  Duquoin  area  showing  the  locations  of  drill  holes 
which  reach  the  level  of  the  Harrisburg  (No.  5)  coal  seam.  Scale,  4  miles 
equal  one  inch. 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUOUOIN 


15 


STRATA  AROVE  HERRIN  COAL 
THE  “('AP-KOCK”  lAMESTONE 

Aliove  the  Herrin  seam  (fig.  4)  in  the  McLeans1)oro  formation, 
the  most  im])ortant  key  stratum  close  to  the  coal  in  this  area  is  a  fairly 
persistent  thick-bedded  limestone  locally  known  as  the  “cap-rock.” 
It  has  a  medinm-fine  texture,  is  of  a  very  dark  gray  color  on  the  fresh 
surface  weathering  to  a  light  brown,  and  contains  marine  fossils, 
among  which  are  Girtyina  ventricosa  as  determined  in  the  field  by 
H.  E.  Culver,  a  hhisnlina  smaller  than  the  forms  found  in  die 
limestone  below  the  Herrin  seam  in  this  region.  This  “cap-rock” 
limestone  formed  in  a  shallow  marine  emhayment,  having  low  lying 
islands,  or  an  irregular  shore-line  extending  into  the  DiKjnoin  area. 
This  is  indicated  by  the  somewhat  lenticular  character  of  the  rock  as 
shown  by  the  logs  of  drill  holes.  Other  apjiarently  lenticular  lime¬ 
stone  horizons  occur  slightly  above  the  “ca])-rock”  limestone.  It 
would  seem  unlikely  that  the  apparent  lenticular  character  of  all  these 
limestone  horizons  would  be  due  to  partial  erosion  of  each  of  them. 

One  of  the  cores  drilled  near  Dowell  over  200  feet  in  depth 
showed  no  limestone  above  the  Herrin  coal.  Another  showed  only 
G  inches  of  limestone.  Others  contained  as  many  as  three  limestone 
formations.  Study  of  the  cores  of  25  holes  drilled  l)y  the  Union  Col¬ 
liery  Company  near  Dowell  furnished  data  for  the  following  table; 


Taple  1. — Summarized  data  regarding  the  thickness  of  several  limestones 
and  the  intervals  between  them  and  the  Herrin  coal. 


Limestone 

Average  thick¬ 
ness 

Average  distance 
of  base  of  lime¬ 
stone  above  the 

top  of  the  Herrin 

coal 

Feet 

Feet 

3.  Medium-gray,  crystalline  . 

8 

82 

2.  Light-gray,  compact  . 

12M. 

49 

1.  “Cap-rock"  limestone  . 

5 

33 

In  the  DiKjUoin  area  the  maximum  known  thickness  of  the  “cap- 
rock”  limestone  is  12  feet,  but  it  averages  4  to  5  feet.  It  is  not  known 
to  be  more  than  lOO  feet  aliove  the  Herrin  coal,  and  is  generally  found 
between  40  and  50  feet  above  it. 


STRATA  15ETWEEN  THE  ‘‘CAP-ROCK’'  LIMESTONE  AND  THE  HERRIN  COAL 

4  he  “cap-rock”  limestone  is  commonly  underlain  by  2  to  G  feet 
of  black  fissile  shale  known  as  “draw  slate”  which  contains  marine 


1() 


STRUCTURE  OF  HERRIX  COAL  NEAR  DUOUOIX 


fossils.  The  strata  between  this  and  the  Herrin  coal  are  mainly  of 
gray,  somewhat  sandy  shale.  In  places  this  shale  is  thin ;  locally  it  is 
absent. 

Thus  at  the  strip  pit  of  the  Black  Servant  Coal  Company  one  mile 
west  of  Elkville  the  “cap-rock”  limestone  which  is  5  to  6  feet  thick 
rests  on  3  or  4  feet  of  black  hssile  shale  which  immediately  overlies 
the  Herrin  coal.  In  the  Jackson  Coal  Company  mine  at  Hallidayboro, 
along  the  main  west  entry  at  the  fault  just  west  of  the  shaft  (see  fig. 
11),  the  “cap-rock”  limestone  is  about  Id  feet  thick  and  in  places  is 
separated  from  the  Herrin  seam  by  only  8  feet  of  shale,  the  upper  half 


Fig.  6.  Convergence  map  showing  interval  in  feet  between  the  base  of 
the  “cap-rock”  limestone  and  the  top  of  the  Herrin  coal.  Secs.  31,  32,  and  33 
in  T.  6  S.,  R.  1  W.  and  secs.  4,  5,  and  6  in  T.  7  S.,  R.  1  W. 


of  which  is  of  the  black  fissile  type.  The  lower  surface  of  the  lime¬ 
stone  is  somewhat  contorted.  These  contortions  are  apparently  the 
result  of  roll-like  disturbances  in  the  underlying  shale,  and  help  ex- 
])lain  the  variable  thickness  of  the  limestone.  Three  miles  farther 
north,  half  a  mile  south  of  the  shaft  of  the  Kathleen  mine  at  Dowell, 
the  “cap-rock”  limestone  is  2o  feet  above  the  top  of  the  Herrin  coal. 
North  of  the  shaft  the  thickness  of  the  strata  between  the  Herrin  coal 
and  the  “cap-rock”  limestone  increases  rather  rapidly,  as  is  shown  by 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIN 


1? 

the  convergence  map,  hgure  h.  The  lines  connect  ])oints  having 
constant  interval  between  the  limestone  and  the  coal,  and  have  the 
values  indicated  by  the  figures  on  the  lines.  Four  miles  northeast  of 
Dowell,  at  the  Majestic  Aline  of  the  Equitable  Coal  and  Coke  Com¬ 
pany,  this  interval  is  almost  100  feet. 

The  variation  in  thickness  of  the  strata  between  the  Herrin  coal  and 
the  “cap-rock”  lime.stone  seems  best  explained  on  the  basis  that  the 
vegetable  matter  which  later  became  the  Herrin  coal  accumulated  on 
an  irregular  surface.  That  such  a  surface,  probably  due  to  erosion, 
existed  is  indicated  by  the  fact  that  the  Herrin  coal  rests  on  “fire  clay” 
of  variable  thickness  or  even  directly  on  the  underlying  limestone. 
Aloreover,  while  the  interval  between  the  Harrisburg  and  Herrin  coals 
is  rather  uniform  so  far  as  known  throughout  the  Duquoin  area,  15 
miles  east  of  Herrin  it  is  much  greater,  averaging  about  100  feet.^ 

W  here  now  there  is  a  Ijelt  of  thick  coal  along  the  eastern  side  of 
the  Duquoin  area,  the  “cap-rock”  limestone  is  farther  above  the  Herrin 
coal  than  is  common  elsewhere.  When  the  Herrin  coal  swamp  first 
existed  along  this  belt  there  was  proliably  a  gentle  valley-like  depres¬ 
sion.  In  this,  conditions  were  such  that  vegetable  material  accu¬ 
mulated  more  rapidly  than  it  did  on  the  surrounding  slightly  higher 
land.  Thus  when  the  lake  or  arm  of  the  sea  in  which  was  deposited 
the  clayey  material  now  making  up  the  “blue-band”  first  came  into 
existence,  there  was  a  greater  thickness  of  a  peaty  material  present  in 
the  lower  belt.  Therefore  now  the  “blue-band”  is  found  farther  above 
the  base  of  the  coal  in  the  belt  of  thicker  coal. 

Somewhat  later,  coal-forming  conditions  again  prevailed,  and  a 
greater  thickness  of  peaty  material  accumulated  in  the  lower  area  as 
before,  until  the  surface  of  the  swamp  was  probably  nearly  level.  As 
a  result  of  this  irregular  accumulation  of  ])eaty  material,  thicker  in 
the  trough  than  elsewhere,  the  greatest  shrinkage  of  the  peat  took 
])lace  in  the  trough  when  the  overlying  muds  were  deposited.  This 
permitted  a  thicker  accumulation  of  mud  here  than  elsewhere  before 
the  material  forming  the  “cap-rock”  limestone  was  deposited." 

Limits  of  the  Area  Underlain  by  the  Herrin  Coal 

ACCURACY  OF  THE  BOUNDARY  LINE 

The  line  across  the  southwestern  part  of  the  map,  Plate  I,  indi¬ 
cating  the  western  boundary  of  the  Herrin  coal  seam  represents  an 
approximation,  except  west  and  southwest  of  Elkville,  where  drilling 

^  Cady.  G.  H..  Coal  Resources  of  District  VI;  Ill.  Mining  Investigations  Bull. 
1.5,  Plate  IV,  1916. 

2  Idem,  pp.  30-32. 


18 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUOUOIN 


by  the  Black  Servant  Coal  Company  has  resulted  in  its  accurate  de¬ 
limitation. 


ABSENCE  OF  COAL  IN  REGION 
AREA  OF  POSSIBLE  NON-DEPOSITION 

There  are  two  large  parts  of  the  Duquoin  area  which  have  not 
been  sufficiently  tested  by  drill  holes.  These  are  in  the  whole  northern 
and  northwestern  portions  of  the  area  (  PI.  I)  and  in  a  large  area  cen¬ 
tered  near  Aliilkeytown,  covering  much  of  the  western  part  of  Frank¬ 
lin  County,  hut  especially  pronounced  to  the  west  of  Sesser  and  Valier. 
In  the  northern  portion  of  this  Mulkeytown  area  the  logs  of  three  drill 
holes  show  no  kferrin  coal,  indicating  the  ]iossihility  of  non-deposition 
of  this  seam  here.  However,  since  a  large  jiortion  of  the  northwestern 
part  of  Franklin  County  has  not  been  drilled  so  far  as  known,  no  defi¬ 
nite  statement  can  be  made  concerning  this  area.  The  theory  sketched 
in  the  jireceding  paragraphs  implies  the  existence  of  a  thick  seam  of 
coal  in  this  area. 

AREAS  OF  SrBSE(JUKNT  EROSION 

Less  than  one  mile  east  of  the  main  line  of  the  Illinois  Central 
Railroad  near  Du([uoin,  two  elongate  north-south  areas  are  shown  on 
Plate  I  from  which  it  is  considered  that  the  Herrin  coal  has  been  re¬ 
moved  by  erosion.  One  of  the  early  Pleistocene  ice-sheets  is  respon¬ 
sible  in  part,  though  some  of  this  missing  coal  was  probably  removed 
in  earlier  epochs.  Because  the  coal  seam  was  so  high  in  these  areas, 
the  protecting  cover  of  sediments  as  well  as  the  coal  were  removed  hy 
weathering  and  erosional  processes.  North  of  St.  John,  the  boundary 
of  the  northern  area  is  unknown,  though  it  is  indicated  by  a  doubtful 
line. 


STRUCTURF 

Structural  Features  Developed  Before  or  Inuring  Consolidation 

SPLITS 

GENERAL  STATEMENT 

W  herever  a  coal  seam  is  divided  into  two  or  more  ])arts  liy  one 
or  more  layers  of  another  rock  called  partings,  the  seam  is  said  to  he 
S])lit.  The  term  is  generally  applied  only  where  the  jiarting  is  bicon¬ 
vex,  like  a  large,  very  thin  lens.  A  split  was  proliably  caused  by  the 
incursion  of  mud-bearing  waters  which  temporarily  and  more  or  less 
locally  interrupted  the  coal- forming  [irocess.  Splits  are  important 
from  the  economic  viewpoint  because  they  prevent  extraction  of  the 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUOUOIN 


19 


coal  under  jiresent  economic  conditions  even  though  they  do  not  in- 
dnence  the  grade  or  quality  of  the  coal. 

Besides  splits  the  coal  has  other  structural  features  that  were  not 
formed  subsequent  to  consolidation.  Although  in  the  main  the  vari¬ 
ous  strata  were  at  one  time  all  essentially  horizontal,  minor  deposi- 
tional  dips  or  grades  were  no  doubt  originally  present.  These,  and 
such  minor  strnctnres  as  rolls  that  developed  at  least  in  part  during 
the  consolidation  of  the  loose  sediments  into  solid  rocks,  are  not  con¬ 
sidered  further  in  this  report. 

THE  MAPPING  OF  SPLIT  AKEAS 

The  areas  of  split  coal  are  shown  on  Plate  I  by  shading  in  black. 
The  degree  of  accuracy  of  the  boundaries  are  indicated  by  solid  lines, 
by  omission  of  definite  boundary  lines,  and  by  the  insertion  of  question 
marks  to  show  whether  the  boundaries  are  certain,  rather  doubtful, 
or  quite  problematical,  respectively. 

N  w. 

Shale 

Shale  parting 


Shale 

0  50  100  150  Feet 

Fig.  7.  Diagrammatic  cross-section  of  split  just  southeast  of  shaft  of 

Majestic  mine. 

It  is  probable  that  patches  of  unsplit  coal  of  workable  thickness 
exist  in  the  large  area  of  split  coal  outlined  around  Mulkeytown. 
Many  sections  in  this  area  have  never  been  drilled,  so  far  as  it  is 
known.  Nine  holes,  each  drilled  in  a  different  section,  southeast, 
south,  and  southwest  of  Mulkeytown  and  none  over  four  miles  from 
town  are  not  shown  on  Plate  I  since  the  logs  were  not  obtainable, 
although  it  was  reported  that  they  all  showed  a  coal  seam  unfavorable 
for  mining  under  present  economic  conditions.  The  boundaries  shown 
for  the  south  and  east  sides  of  this  area  are  particularly  questionable. 

DETAILED  DESCRIPTIONS  OF  AREAS  OF  SPLIT  COAL 

Majestic  mine. — An  excellent  example  of  a  split  has  been  com¬ 
pletely  delimited  in  the  workings  of  the  Majestic  mine.  The  outline 
of  the  split  appears  on  Plate  I  in  the  W.  ^  of  sec.  33,  T.  6  S.,  R.  1  A  . 
a  short  distance  southeast  of  the  shaft.  Figure  7  shows  a  diagram¬ 
matic  cross-section  compiled  from  data  obtained  from  a  study  in  the 


Shale 


20 


STRUCTURE  OF  HERRIX  COAL  NEAR  DUQUOIX 


mine  and  the  log  of  a  drill  hole  which  penetrates  the  split  area.  Figure 
8  shows  a  large-scale  diagram  of  the  north  side  of  this  split  as  it  ap¬ 
pears  in  one  cross-section.  The  thicker  part  of  the  seam  generally 
follows  the  upper  side  of  the  shale  parting  in  the  iMajestic  mine,  al¬ 
though  the  opposite  is  true  at  the  place  represented  in  figure  8.  The 
diagram  illustrates  the  fact  that  the  bedding  in  the  coal  runs  parallel 
to  its  surfaces  in  this  split,  and  the  dip  of  the  split  coal  near  the  edge 
averages  about  10°. 


Fig.  8.  Detail  of  north  side  of  split,  Majestic  mine  ( E.  rib,  entry  8  S., 
main  E.).  Scale,  1  inch  equals  2.8  feet. 


The  west  side  of  a  larger  split  has  been  delimited  in  the  eastern 
part  of  the  iMajestic  mine,  and  is  shown  on  Plate  I  in  the  extreme  east- 
central  part  of  sec.  23,  T.  6  S.,  R.  1  W..  about  one  mile  east  of  the 
shaft.  The  thicker  part  of  the  seam  rises  steeply  here  ;  entries  have 
been  driven  on  as  high  as  a  30  degree  pitch  for  short  distances  in  this 
thick  U])per  part.  The  area  of  this  split  is  unknown,  as  the  location  of 
its  eastern  boundary  has  not  been  determined  precisely,  but  it  seems 
probable  that  it  is  not  much  larger  than  half  a  square  mile  in  area  at 
the  most,  as  in  this  district  known  splits  which  cause  steeply-dipping 
coal  beds  are  not  large. 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIN 


^  J 


.  M idkcvfozvii  area.— in  the  northwestern  ])art  of  sec.  15,  1'.  (>  S., 
R.  1  E.,  in  the  western  part  of  the  Old  Ben  Coal  Corporation  mine 
Xo.  11,  the  workings  have  delimited  what  ap|)ears  to  be  the  northeast 
corner  of  a  larger  area  of  split  coal.  The  parting  starts  with  almost 
paper-thinness  near  the  middle  of  the  8-foot  coal  seam  along  entry 
9  \\h  off  4  X.  off  the  main  west.  Farther  west  it  increases  very  gradu¬ 
ally  in  thickness  until  at  the  end  of  the  entry,  a  total  distance  of  (>50 
feet,  it  is  about  2  feet  thick.  The  parting  is  medium-gray  shale  con¬ 
taining  a  little  line  sand.  The  blue-hand,  which  is  about  4  inches  thick, 
])ersists  near  the  middle  of  the  lower  part  of  the  seam.  On  incom¬ 
plete  evidence  it  seems  probable  that  this  split  area  is  but  a  small  frac¬ 
tion  of  a  much  larger  area  of  s])lit  coal,  as  indicated  on  Idate  1.  Ibis 
area  apparently  includes  Alulkeytown,  the  southern  ]xirt  of  Chris- 
tO])her,  and  a  broad  area  southwest  and  west  of  Christopher  reaching 
within  two  miles  of  Zeigler,  Royalton,  Elkville,  Dowell,  and  Old 
Duquoin. 

Hallidayboro-B itsh  area. — W  hat  seems  to  be  a  separate  area  of 
split  coal  is  outlined  on  Idate  1  between  Hallidayboro  and  Bush  al¬ 
though  the  area  may  be  a  locality  in  which  the  “blue-band”  is  excessivelv 
thick.  Evidence  in  favor  of  this  conception  apjiears  in  the  eastern 
j)art  of  the  Jackson  Coal  Conqiany  mine  at  Hallidayboro  in  XW\b 
sec.  29,  T,  T  S.,  R.  1  W  .,  where  the  “blue-band”  is  reported  to  increase 
considerably  in  thickness,  averaging  about  18  inches.  The  most  pro¬ 
nounced  feature  of  this  area  is  the  basin  shown  by  structure  contour 
lines  in  the  XIC  Ft  'H,  T.  1  S.,  R.  1  \V.  It  seems  probable 

that  this  notable  structural  depression  is  at  least  in  part  due  to  a  split, 
the  contours  being  based  on  the  lower  part  of  the  seam. 

ORIGIN 

XW  one  mode  of  origin  will  account  satisfactorily  for  all  these 
various  types  of  splits,  although  they  were  formed  at  the  same  time 
that  vegetable  matter  later  converted  into  Herrin  coal  was  accumulat¬ 
ing  in  the  neighborhood.  During  the  latter  stages  of  the  Carbondale 
epoch,  when  most  of  the  area  was  a  swamp  in  which  a  luxuriant  vege¬ 
tation  grew,  due  to  small  irregularities  in  the  surface  of  the  land,  tem- 
])orary  lakes  or  ponds  were  present  in  certain  localities.  The  split 
area  completely  outlined  in  the  Majestic  mine  marks  the  site  of  one 
such  pond  near  the  close  of  the  Carbondale  epoch.  After  a  certain 
amount  of  vegetable  matter  had  accumulated  at  this  place,  which  as 
indicated  in  figure  7  was  probably  marked  by  a  depression  in  the  under¬ 
lying  rocks,  physical  conditions  changed  sufficiently  so  that  mud  was 
carried  into  the  pond  that  already  existed  there  or  was  formed  at  that 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIX 


-v  -v 


time.  If  a  pond  existed  previously,  it  was  so  shallow  as  to  offer  no 
real  impediment  to  the  growth  of  vegetation.  Possibly  the  mud  was 
carried  in  by  a  stream  and  dropped  as  a  delta  deposit,  notably  com¬ 
pressing  the  vegetable  matter.  I'hat  this  split  is  a  deposit  of  the  delta 
type  is  suggested  perhaps  by  its  small  area,  about  ‘20  acres,  and  its 
relatively  great  thickness,  probably  over  50  feet. 

The  split  partially  outlined  in  the  eastern  part  of  the  iMajestic 
mine  may  also  be  of  the  delta  type  as  it  is  probably  of  limited  extent. 

On  the  other  hand,  the  s]ilit  discovered  in  the  northwestern  part 
of  the  Old  Ben  Coal  Corporation  mine  Xo.  11  near  Christopher  seems 
to  be  a  typical  lake  or  sea  deposit.  Its  gradual  increase  in  thickness 
indicates  a  relatively  thin  deposit  over  a  rather  broad  area.  W  bile  it 
is  mapped  as  part  of  the  large  Alulkeytown  split  area,  it  seems  certain 
that  no  lake  or  arm  of  the  sea  covered  the  whole  area  at  one  time. 
This  is  indicated  by  the  fact  that  no  single  shale  parting  appears  to  be 
represented  in  the  different  drill  hole  logs  throughout  the  area.  In 
fact,  in  some  cases  several  partings  appear  in  a  single  drill  hole  log, 
showing  that  mud  deposits  formed  in  several  ponds  or  lakes  that  were 
not  contemporaneous.  It  seems  probable  that  locally  these  deposits 
do  not  overlap,  and  workable  coal  might  then  be  present  in  certain  re¬ 
stricted  patches  of  the  large  iMulkeytown  split  coal  area. 

The  other  area  of  s])lit  coal,  that  lies  between  Hallidavboro  and 
Bush,  is  in  part  a  lake  or  sea  deposit  of  the  type  just  described.  If 
the  structural  de|)ression  shown  on  Idate  I  in  the  X^E.  sec.  27, 

T.  7  S..  R.  1  is  caused  by  a  split,  it  would  seem  to  resemble  the 
type  described  in  the  Majestic  mine,  and  conceivably  might  represent 
an  old  delta  deposit. 

Structural  Features  Developed  after  Consolidation 

GENERAL  CONSIDERATIONS 

The  rocks  of  the  Duquoin  area  have  been  slightly  disturbed  sub¬ 
sequent  to  their  formation.  V\  bile  as  originally  deposited  and  changed 
by  consolidation,  certain  types  of  structures  were  present,  such  as  rolls 
and  splits,  subsequent  forces  have  produced  much  more  pronounced 
irregularities.  The  coal  seam,  once  essentially  continuous,  has  locally 
been  faulted  ;  that  is,  broken  and  displaced  or  offset  along  a  more  or 
less  irregular  surface,  the  fault  plane.  In  addition,  the  whole  area 
has  been  gently  warped  and  now  is  a  part  of  the  large  structural  basin 
of  Pennsylvanian  rocks  which  covers  the  southern  two-thirds  of  Illi¬ 
nois,  and  adjacent  parts  of  Indiana  and  Kentucky.  The  strata  of  the 
Duquoin  area  have  a  prevailing  northeasterly  diji  towards  the  center 
of  the  basin,  except  where  minor  forces  have  produced  local  modih- 
cations. 


STRUCTURE  OF  IIERRIX  COAL  NEAR  DUCJUOIN 


STRUCTURE  CONTOURS 

The  structure  in  an  area  of  gently  dipping  rocks  such  as  near 
Duquoin  is  l)est  shown  by  means  of  structure  contours,  although  cross- 
sections,  block  drawings,  sketches,  and  ])hotographs  are  also  of  value. 
Structure  contours  afford  an  accurate  representation  of  structural  con¬ 
ditions  ;  other  methods  of  showing  structure  are  likely  to  exaggerate 
the  actual  conditions. 


Fig.  9. — Surface  of  the  Herrin  coal  as  it  would  appear  if  all  the  overlying 
material  were  removed.  The  diagram  shows  the  significance  of  the  struc¬ 
tural  contour  line.  (Shading  by  George  H.  Renshawe.) 

Contours  are  lines  drawn  connecting  points  on  any  surface  that 
have  the  same  altitude.  This  surface  may  be  the  land  surface,  or  it 
may  lie  a  buried  surface,  such  as  the  top  or  base  of  a  coal  seam.  In 
the  case  of  a  buried  surface,  the  lines  are  known  as  structure  contours, 
hdgure  !)  by  hTed  kl.  Kay  makes  clear  the  use  of  structure  contours. 


24 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIN 


County  lioiindaries  are  sketched  on  this  diagram;  part  of  Franklin 
County  is  shown  in  the  lower  right-hand  corner.  The  vertical  dis¬ 
tance  between  successive  contour  lines,  known  as  the  contour  interval, 
is  arldtrarily  chosen.  In  figure  9,  this  is  50  feet.  On  Plate  I  it  is 
20  feet  except  in  the  northwestern  part  of  the  maj),  where  for  lack  of 
sufficient  data  an  interval  of  100  feet  is  used.  The  surface  shown  by 
structure  contours  on  Plate  I  is  the  base  of  the  Herrin  coal  or  the  top 
of  the  underlying  beds.  This  was  chosen  in  preference  to  the  top  of 
the  coal,  because  mine  maps  generally  show  elevations  along  the  floors 
of  the  entries,  which  practically  correspond  to  the  base  of  the  coal 
bed.  Where  the  contours  are  closely  spaced,  this  surface  has  a  rel¬ 
atively  steep  inclination ;  where  far  apart,  it  is  nearly  horizontal. 

ACCURACY  OF  THE  STRUCTURE  CONTOURS 

41ie  accuracy  of  the  structure  contours  on  Plate  I  depends  mainly 
upon:  (  1)  the  accuracy  of  the  base  maps  used;  (2)  the  number  and 
distrilnition  of  the  drill  holes  whose  logs  are  used;  (3)  the  accuracy 
of  the  logs  ;  (4)  the  accuracy  of  the  figures  obtained  for  the  elevations 
of  the  surface  at  the  locations  of  the  drill  holes  ;  and  (5)  the  accuracy 
of  the  elevations  shown  on  the  mine  maps  used. 

As  topographic  ma])S  were  not  available  for  the  northern  half 
of  the  area,  there  was  considerable  uncertainty  in  locating  and  obtain¬ 
ing  the  surface  elevations  of  some  holes  in  that  part  of  the  area.  In 
the  north-central  and  northwestern  parts,  structure  contour  lines  are 
either  not  shown,  or  else  the  contour  interval  is  increased  to  lOO  feet 
due  to  the  paucity  of  both  mines  and  available  drill  hole  logs.  44ie 
absence  of  contours  does  not  indicate  lack  of  coal. 

In  general  structure  contours  arc  less  accurate  than  surface  con¬ 
tours,  because  the  data  from  which  they  are  prejiared  are  less  com¬ 
plete.  Data  from  drill  hole  logs  and  other  sources  give  the  elevation 
of  the  base  of  the  coal  seam  at  a  limited  number  of  points.  Contours 
are  then  drawn  which  are  in  harmony  with  these  values,  but  minor 
irregularities  in  the  coal  seam  are  generally  not  shown  on  the  ma|). 
Solid  lines  indicate  very  accurate  data  taken  from  levels  on  mine  maps; 
long  dashed  lines  show  doulitful  or  somewhat  scattered  data;  and 
short  dashed  lines  are  in  more  or  less  speculative  positions. 

WARPING 

DUQIIOIX  ]M()XOCI.IXAL  FLEXURE 

The  most  pronounced  feature  modifying  the  general  north-east¬ 
erly  dip  characteristic  of  the  rocks  of  the  area  is  the  Ducpioin  mono- 
clinal  flexure  trending  N.  10°  E.  from  Elkville  ])ast  Dowell  and  one 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIN 


25 


mile  east  of  Diiquoin.  This  is  clearly  shown  in  figure  9.  Previous 
authors  have  commonly  referred  to  this  as  an  anticline,  Init  it  is  more 
accurate  to  call  it  a  monoclinal  flexure,  since  in  general  opposing  dips 
are  absent  and  the  dip  is  rarely  greater  than  5°  to  (P. 

Idle  Du(|uoin  monoclinal  flexure  is  shown  on  Iflate  1  by  the  close¬ 
ly-spaced  contours  drawn  on  the  base  of  the  Herrin  coal  seam.  It 
is  especially  marked  between  Dowell  and  an  area  about  two  miles 
east  of  St.  John,  from  where  it  appears  to  liroaden  out  to  the  north¬ 
ward  gradually,  though  accurate  data  are  lacking  in  this  area.  It 
can  be  traced,  however,  as  far  north  as  the  Sandoval  dome  a  few 
miles  north  of  Centralia.  South  of  Elkville  or  Hallidayhoro  it  loses 
its  monoclinal  character,  and  the  contours  bend  ofif  in  a  southeasterly 
to  easterly  direction  conforming  to  the  general  regional  dip. 

Except  in  areas  of  split  coal  the  maximum  dip  observed  in  the 
strata  of  the  Duquoin  monoclinal  flexure  was  8^4°,  which  is  equiva¬ 
lent  to  a  grade  of  per  cent.  The  average  easterly  dip  of  the 

strata  on  this  flexure  in  T.  G  S.,  R.  I  where  it  is  best  developed 
is  about  5°  or  an  8^.  per  cent  grade. 


FAULTING 

GENERAL  CITARACTER  OF  THE  FAULTS 

Most  of  the  faults  in  the  Duquoin  area  are  of  the  normal  type ; 
that  is,  the  fault  plane  dips  toward  the  downthrow  side  as  in  figure  11. 
In  general,  therefore,  where  the  coal  seam  is  lost  at  a  fault  plane 
the  rule  is  to  follow  the  fault  plane  in  the  direction  of  the  obtuse 
angle  between  the  coal  seam  and  the  fault  plane  in  order  to  reach 
the  lost  part  of  the  seam.  Mdiere  the  fault  plane  makes  an  angle  of 
45°  to  50°  or  less  with  the  horizontal  as  in  figure  12,  the  fault  is 
likely  to  be  of  the  reverse  type.  In  this  case  the  fault  plane  dips  toward 
the  upthrow  side,  and  in  order  to  find  the  hidden  part  of  the  seam 
it  is  necessary  to  follow  the  fault  plane  in  the  direction  of  the  acute 
angle.  Eault  planes  do  not  extend  indefinitely  in  any  direction.  Erom 
a  place  of  maximum  vertical  displacement  the  amount  of  offset  gener¬ 
ally  decreases  in  both  directions  along  the  fault  line.  Although  there 
is  a  general  decrease,  in  most  cases  this  is  not  uniform  ;  the  displace¬ 
ment  in  a  given  direction  while  decreasing  on  the  whole  may  actually 
increase  locally. 

SYSTEMS  OF  FAIMTING 

Eaulting  in  the  area  so  far  as  known  is  confined  to  two  lielts  or 
systems.  One  trends  about  N.  10°  E.  parallel  to  and  along  the  east 
side  of  the  Duquoin  monoclinal  flexure  (PL  I).  The  other  trends 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUOUOIN 


•>() 


east-southeasterly  through  Hallidayboro  and  Royalton.  The  former 
system  contains  faults  whose  individual  trends  correspond  with  the 
trend  of  the  system  ;  in  the  latter  system,  which  is  the  wider,  the  faults 
are  mainly  short  cross- faults  that  trend  south-southeast  roughly 
at  45°  to  the  direction  of  the  system.  It  is  to  be  noted,  however, 
that  the  two  faults  showing  the  greatest  amount  of  displacement  which 
are  shown  on  Plate  I  lie  in  this  second  system  and  trend  approximately 
parallel  to  the  direction  of  the  system. 

The  N.  10°  E.  system  appears  to  be  short;  there  is  no  evidence 
that  it  extends  beyond  the  limits  of  Plate  I.  Its  close  association  with 
the  Duquoin  monoclinal  flexure  suggests  that  both  structures  were  pro¬ 
duced  approximately  at  the  same  time  as  a  result  of  the  same  forces. 
There  is  no  evidence  that  lateral  compressive  forces  were  of  more 
than  minor  importance.  A  gradual  settling  of  the  beds  on  the  east 
side  of  the  flexure  accompanied  by  minor  faulting,  in  part  of  the 
graben  type,  appears  to  offer  a  simple  yet  logical  explanation  of  the 
present  structure. 

The  other  system,  however,  is  apparently  a  part  of  the  “east-west 
fault  zone”  described  by  Cady^  in  coal  district  \  I  to  the  east. 
Cady  shows  the  system  trending  about  S.  70°  E.  Extended  in  a  west¬ 
erly  direction,  Cady’s  “east-west”  fault  zone  would  include  Dowell. 
It  is  possible  that  the  fault  mapped  by  Shaw  and  Savage^  in  the 
northwestern  part  of  the  Murphysboro  Ouadrangle  also  belongs  in 
this  system. 

It  seems  probable  that  a  cross-pattern  of  minor  faults  may  lie 
at  the  juncture  of  these  two  fault  systems.  The  logical  area  in  which 
to  expect  such  a  fault  pattern  is  immediately  to  the  northeast  of  Elk- 
ville,  where  the  closely-spaced  contours  (Idate  I)  bend  sharply  to  the 
southeast.  Data  to  prove  the  existence  of  such  faults  are  not  avail¬ 
able,  though  recent  development  work  in  the  southern  part  of  the 
Kathleen  mine  near  Dowell  has  uncovered  a  fault  trending  S.  15°  E. 
which  seems  to  be  a  curved  extension  of  one  of  the  X.  10°  E.  faults 
so  common  in  the  mine. 

DESCRIPTTOX  OF  THE  FAULTS 

Faults  near  JVcaz'cr. — The  largest  measured  fault  in  the  area  is 
the  one  trending  ESE.  in  Old  Ben  Coal  Corporation  Aline  X"o.  20 
near  WTaver,  Whlliamson  County.  As  this  mine  was  closed  in  the 

3  Cady,  G.  II.,  Coal  Re.sources  of  District  VI:  Ill.  IMining-  Investigations 
Bull.  15,  p.  82,  1916. 

*  Shaw,  E.  W.,  and  Savage,  T.  E.,  U.  S.  Geol.  Survey  Geol.  Atlas,  :Mur- 
physboro-Herrin  folio  (No.  185),  1912. 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIN 


27 


suninier  of  1923  no  underground  studies  could  be  made.  It  was  re¬ 
ported  that  where  the  main  N\\\  entry  strikes  the  fault  plane,  the 
coal  seam  has  a  downthrow  of  about  44  feet,  as  shown  by  a  drill  hole 
a  short  distance  beyond  the  end  of  the  entry.  On  the  south  side  of 
the  fault  plane  for  a  short  distance  the  ccjal  di])s  3}4°  to  the  south 
along  the  entry,  ddie  other  faults  in  this  mine  are  much  smaller, 
the  next  largest  one  having  a  maximum  known  dis])lacement  of  22 
feet.  44iis  was  measured  in  the  X\\’.  ^  of  the  X^E.  ^  of  sec.  2,  T. 
8  S.,  R.  1  E.,  along  entry  3  \\k  off  the  main  X^.  To  the  southeast 
this  fault  disappears  in  slightly  less  than  one  mile.  Its  extension  to 
the  northwest  is  unknown.  44ie  other  faults  in  this  mine  (Plate  I) 
have  maximum  throws  of  about  10  feet.  So  far  as  is  known,  all  are 
of  the  normal  type. 


Feet 

Fig.  10.  Cross-section  (looking  north)  of  main  fault  in  No.  2  mine  at  Bush. 

Faults  Near  Royalton. — It  was  impossible  to  see  the  fault  that 
se])arates  the  two  Royalton  mines,  but  it  was  described  as  consisting  of 
a  series  of  parallel  slips  with  a  total  downthrow  of  about  40  feet  on  the 
southwest  side.  The  coal  bed  dips  gently  to  the  northeast  on  both  sides 
of  the  fault  zone;  on  the  northeast  side  it  is  very  gentle;  on  the  other 
side  it  is  slightly  steeper,  except  just  at  the  fault  where  it  is  at  a  rela¬ 
tively  high  angle. 

This  belt  of  steeply  dipping  beds  to  the  northeast  is  too  narrow 
to  be  shown  by  contours  on  a  map  the  size  of  Plate  I ;  thus  the  large 
throw  of  this  fault  is  not  indicated. 

There  is  only  one  fault  of  much  importance  exposed  in  the  work¬ 
ings  of  Mine  Xo.  2  of  the  W  estern  Coal  and  Mining  Company  in  the 
SE.  sec.  31,  T.  7  S.,  R.  1  E.,  approximately  one  mile  north  of  Bush. 
It  is  the  one  shown  by  dashed  lines  on  Plate  I  curving  in  a  northerly 
direction.  It  is  a  normal  fault  with  the  downthrow  on  the  east  side. 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUOUOIN 


\\  here  the  1-2  E.  entries  off  the  main  N.  intercept  the  fault,  the  throw 
is  blit  10  feet;  but  about  11 00  feet  farther  northwest,  where  the  3-4  E. 
entries  off  the  main  X.  intercept  it,  the  throw  is  21  feet.  The  5-6  E. 
entries  off  the  main  N.  end  at  the  fault  plane.  It  appears  that  the 
throw  along  this  jilane  increases  to  the  north,  where  it  may  become 
as  much  as  50  or  60  feet.  In  cross-section  along  the  4  E.  entry  off 
the  main  X".,  this  fault  (fig.  10)  is  double,  and  the  two  planes  are 
about  30  feet  ajiart. 

Extending  northeast  from  this  fault  is  postulated  a  short  fault 
with  a  maximum  throw  of  about  60  feet  with  downthrow  on  the 
northwest.  Extending  in  a  northwesterly  direction  is  shown  on  Plate  I 
a  possible  fault  with  a  maximum  downthrow  on  the  northeast  side 
of  about  100  feet.  It  appears  to  die  out  in  Jackson  County.  These 
two  hypothetical  faults  are  based  on  drill  hole  records. 


Pig.  11.  Cross-section  of  fault  in  the  main  west  entry  of  the  mine 
of  the  Jackson  Coal  Company  at  Hallidayboro.  The  dashed  line  shows 
the  profile  of  the  base  of  the  entry. 


faults  near  Hallidayboro. — 44ie  two  main  faults  indicated  on 
Plate  I  in  the  workings  of  the  mine  of  the  Jackson  Coal  Company  at 
Hallidayboro  are  both  of  some  interest.  The  larger  fault,  which  is  of 
the  normal  type,  is  shown  diagrammatically  in  figure  II  where  it  cuts 
the  main  west  entry  about  400  feet  from  the  shaft.  The  displacement 
in  the  ])lane  of  the  section  is  approximately  30  feet.'"^  It  is  thought 
that  this  is  nearly  a  maximum  figure  for  this  fault,  and  that  the  throw 
is  smaller  to  the  northwest  and  southeast.  At  the  north  end  of  entry 
9  Xb  off  the  main  \\b  in  the  XE.  SE.  J4  sec.  19,  T.  7  S.,  R.  I  \\b, 
the  throw  of  this  fault  is  only  7  feet. 


Along-  the  fault  plane  there  i.s  a  vein  of  calcite  about  an  inch  thick,  asso¬ 
ciated  with  which  are  numerous  capillary,  fibrous  crystals  of  melanterite 
(FeSOt  TH^O)  a  pale  green  mineral  with  a  vitreous  luster  and  a  pronounced 
astringent,  metallic  taste.  Both  of  these  minerals  are  commonly  present  along 
the  fractures  found  in  the  coal  of  the  area. 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIN 


2U 


The  small  fault,  as  indicated  in  figure  1*T  apjiears  to  he  of  the 
reverse  type.  This  fault  was  probably  caused  by  compressive  forces, 
and  its  position  fixed  by  a  pre-existing  roll.  The  roll  in  the  coal  seam 
on  the  west  side  of  the  fault  is  better  shown  in  the  main  east  entry 
than  it  is  in  the  back  east  entry  represented  in  figure  \2.  Along  the 
main  east  entry  a  stringer  of  coal  about  (>  inches  thick  branches  up 
from  the  fault  plane,  and  there  is  no  actual  faulting  along  the  west 
side  of  the  roll,  such  as  that  indicated  in  figure  \2  by  the  dotted  line. 
The  bedding  of  the  coal  within  the  rolled  area  is  notably  disturbed,  in 
places  appearing  slightly  contorted.  The  apparent  throw  of  this  fault 
is  9  to  10  feet  where  crossed  by  the  main  east  entry.  It  is  ])robably 
less  than  this  to  the  northwest  and  southeast,  as  many  rooms  in  the 
old  workings  were  holed  through  it. 


West 


Fig.  12.  Cross-section  (looking  south)  of  fault  of  the  reverse  type  in  the 
back  east  entry  of  the  mine  of  the  Jackson  Coal  Company  at  Hallidayboro. 
The  dashed  lines  show  the  profile  of  the  entry.  Scale,  1  inch  equals  about 
13  feet. 


Faults  near  Dozvell. — From  the  viewpoint  of  faulting,  the  most 
interesting  mine  in  the  area  is  the  Kathleen  mine  at  Dowell.  The 
workings  of  this  mine  are  shown  in  some  detail  on  Plate  II.  With 
one  exception  all  the  faults  so  far  discovered  trend  in  a  direction  paral¬ 
lel  to  the  Duquoin  monoclinal  flexure.  They  are  limited  to  the  eastern 
and  southern  parts  of  the  workings.  In  the  rest  of  the  mine  the  coal 
seam  has  a  rather  uniform  easterly  dip  of  approximately  3^°.  Figure 
13  is  a  generalized  cross-section  of  the  faulted  portion  of  the  main 
east  entry  with  a  few  minor  displacements  omitted.  Faults  Nos.  2,  5,  f), 
and  possibly  7  have  smaller  displacements  to  the  south  than  indicated 
in  the  figure,  while  the  reverse  is  true  of  Nos.  1  and  4.  According  to 
recent  report,  fault  No.  1  has  a  throw  of  35  to  40  feet  about  half  a  mile 


30 


STRUCTURE  OF  HERRIX  COAL  NEAR  DUOUOIX 


south  of  the  main  east  entry,  where  Xo.  5  coal  seam  appears  in  the 
face  of  9  and  10  east  entries  off  the  main  south  entry.  Fault  X^o.  3  has 
a  larger  displacement  a  quarter  of  a  mile  to  the  north,  but  still  farther 
north  it  dies  out  rapidly.  Presumably  it  has  a  smaller  displacement  to 
the  .south  of  the  main  east  entry  than  is  indicated  in  hs^ure  13.  The 
only  other  important  fault  so  far  discovered  in  the  Kathleen  mine  (see 
PI.  II)  is  about  500  feet  west  of  XT.  1.  but  is  south  of  the  main  east 
entry. 

Figure  13  shows  that  the  dominant  faulting  in  the  Kathleen  mine 
is  of  the  normal  type,  and  that  the  net  result  of  the  faulting  is  a  minor 
structural  trough.  This  trough-like  character  dies  out  rapidly  to  the 
north,  due  to  the  lack  of  persistence  of  fault  X^o.  3  along  the  west  side. 
To  the  south  the  detailed  conditions  are  unknown.  ^^Tst  of  Dowell,  as 
well  as  east  of  the  faulted  area  (see  Plate  I),  the  coal  seam  is  nearly 
horizontal,  though  it  does  have  an  extremely  gentle  easterly  dip. 


'1-2  S.  entries 
0  100  200  Feet 


lOO  Ft  above 
sea  level 


Fig.  13.  Profile  of  faulted  part  of  the  Herrin  coal  seam  along  the  main 
east  entry  of  the  Kathleen  mine  at  Dowell.  Fault  Xo.  2  is  not  shown  on 
Plate  I. 


Although  the  major  faulting  in  the  Kathleen  mine  is  of  the  normal 
type,  there  has  keen  some  reverse  faulting  on  a  small  scale,  as  shown  by 
the  detailed  sketch  (fig;.  Id).  It  seems  there  have  been  two  movements 
here ;  the  earlier  a  normal  fault,  the  later  a  reverse  fault.  The  first 
fault  was  along  the  plane  including  A-B  and  its  now  offset  continuation 
C-E.  The  throw  amounted  to  about  1  feet,  with  downthrow  on  the 
west  side.  The  second  fault  was  horizontal  along  B-C  with  a  displace¬ 
ment  of  5  feet  9  inches  in  a  direction  perpendicular  to  the  strike  of  the 
earlier  fault.  It  is  to  be  noted  that  the  plane  of  the  second  fault  in¬ 
cludes  the  top  of  the  downfaulted  part  of  the  coal  seam,  and  the  “blue- 
band”  in  the  other  part  of  the  seam,  both  of  which  are  relatively  weak 
surfaces.  It  was  not  possible  to  determine  the  actual  directions  of 
movement,  but  many  of  the  fault  planes  in  the  Kathleen  mine  show 
apparently  horizontal  slickensides,  as  if  at  least  in  part  the  strata  moved 
laterally  along  the  fault  plane. 

Essentially  identical  relationships  are  seen  in  other  parts  of  this 
mine,  such  as  along  the  main  east  entry  whgre  it  cuts  faults  X'^os.  1  and 


STRUCTURE  OF  TIERRIX  COAL  NEAR  DUOUOIX 


;n 


2.  Aloreovcr,  sonic  of  the  cross-sections  of  the  larger  faults  show 
characteristics  which  are  in  harmony  with  these  relationships.  Thus 
in  hgure  15,  the  folding  of  the  bedding  planes  in  the  coal  indicates  that 
com])ressive  forces  followed  those  which  caused  the  typical  normal 
faulting.  Although  the  hedding  planes  in  the  coal  on  the  west  side 
of  this  fault  jilane  jirohahly  once  di]iped  down  rather  steeply  to  the 
east,  as  would  have  been  caused  by  the  drag  of  the  down-dropping 
strata  on  the  east  side  of  the  plane,  later  compressive  forces  jiresum- 
ahly  modihed  this  dip,  or  even  reversed  it,  as  shown  in  hgure  15.  Thus 
the  liedding  of  the  coal  scam  in  the  upper  part  of  the  diagram  near 
the  fault  })lane  is  almost  parallel  to  the  fault  ])lane,  hut  the  strata  are 

Watt  East 


0  1  2  3  4  5  Feet 


Pig.  14.  Detailed  sketch  cf  fault  in  north  rib  of  entry 
5  W.  (100  feet  west  of  the  main  south)  in  the  Kathleen 
mine  at  Dowell. 

bent  upAvards.  The  maximum  thickness  of  the  gouge  zone  shown  is 
aliout  six  inches,  and  it  is  made  up  almost  entirely  of  shale. 

Ihj lilts  cast  of  Diiquoiii. — The  map  of  the  abandoned  Davis  or 
Queen  mine  in  the  NW.  hi  tif  sec.  15,  T.  (5  S.,  R.  1  Ah,  shows  two 
nearly  parallel  faults  (PI.  1)  trending  in  about  the  same  direction  as 
the  faults  in  the  Kathleen  mine.  It  seems  probable  that  these  pro¬ 
duce  a  shallow  structural  rift,  similar  to  the  trough  of  the  Kathleen 
mine  (lig.  l-l).  The  west  fault  is  the  larger,  and  has  a  maximum 
throw  near  the  shaft,  where  it  amounts  to  about  20  feet,  but  decreases 
to  about  eight  feet  before  it  leaves  the  mine  workings.  The  offset  of 


/ 


32 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUQUOIN 


the  east  fault  is  only  about  10  feet.  Further  data  obtained  on  the 
faults  in  this  old  mine  are  highly  conflicting,  although  it  is  known  that 
to  the  south  of  the  shaft  the  east  fault  dies  out  within  the  mine  work¬ 
ings.  From  a  study  of  the  logs  of  available  drill  holes,  it  seems  prob¬ 
able  that  the  west  fault  extends  as  far  south  as  the  SE.  ^4  of  ^oc.  21, 
T,  6  S.,  R.  1  \\b,  as  shown  on  Plate  L 


Base  of  entry 

0  12  3  Feet 


Fig.  15.  Cross-section  of  fault  No.  3  (fig.  13),  north  rib,  main  east 
entry,  Kathleen  mine  at  Dowell.  Curved  lines  indicate  prominent  bedding 
planes  in  the  coal  seam. 


PRACTICAL  ECONOMIC  ASPECTS 

\k\LUE  OF  THE  Structure  Contour  Map,  Plate  I 

Plate  I  shows  the  lay,  the  continuity,  and  the  areal  limits  of  the 
Herrin  coal,  the  approximate  location  and  extent  of  certain  areas  of 


STRUCTURE  OF  HERRIN  COAL  NEAR  DUOUOIX 


•>  •> 


split  coal  and  faults  whose  displacements  can  be  computed  from  con¬ 
tours  on  both  sides  of  the  fault  lines.  With  the  aid  of  the  structure 
contours  it  is  ])0ssible  to  determine  the  de])tb  to  the  Herrin  coal  seam 
at  any  point  where  the  surface  elevation  is  known.  If  the  coal  is 
above  sea-level  its  elevation  as  shown  by  contours  should  he  subtracted 
from  the  elevation  of  the  surface  to  hud  the  depth;  in  case  the  coal 
is  below  sea-level,  these  two  elevations  should  lie  added. 

Effects  of  Faulting  on  ^Mining  ^Methods  at  Dowell 

In  driving  the  main  cast  entry  of  the  Kathleen  mine,  when  fault 
Xo.  3  ( hg.  13  and  Id.  II)  was  encountered,  the  entry  was  continued 
sloping  rather  steeply  to  the  east  until  it  again  reached  the  base  of  the 
seam  near  fault  No.  d.  On  continuing  to  the  east,  faults  Nos.  3,  G 
and  T  were  encountered  and  necessitated  a  rather  rapid  rise  in  the 
level  of  the  entry,  d'he  result  was  two  steep  grades  o|)posing  each 

other  along  a  main  haulage  way.  Later  the  roof  of  the  main  east 

entry  was  shot  down  until  the  entry  was  nearly  level  between  faults 
Nos.  3  and  T.  The  back  east  entry  was  not  changed,  however,  as  it 

was  needed  to  remove  the  coal  from  the  base  of  the  trough.  Entries 

driven  north  and  south  from  the  back  east  entry  at  the  base  of  the 
trough  are  used  for  the  removal  of  the  low  coal.  The  south  entry 
was  driven  slightly  west  of  south  to  parallel  the  faults. 

Entries  running  west  from  entry  1  south  off  the  back  east  can  be 
continued  across  the  trough  and  reach  coal  X"o.  5  with  no  pronounced 
change  in  level.  Thus  if  in  the  future  it  is  desirable  to  mine  this  lower 
seam,  it  can  he  done  without  deepening  the  shaft. 

Importance  of  Drilling 

Before  the  shafts  of  prospective  new  coal  mines  are  started,  it 
is  economical  to  ascertain  the  conditions  affecting  the  coal  seam  by 
drilling.  Along  the  faulted  belts  jtreviously  described  ( ]).  25),  or  in 
the  areas  outlined  on  Plate  I  as  being  underlain  by  split  coal,  core¬ 
drilling  is  highly  desirable.  Sufficient  holes  should  be  put  down  to 
leave  no  doubt  about  the  character,  continuity  and  attitude  of  the  coal. 
\\  here  the  coal  seam  is  siilit,  drill  cores  would  show  the  thickness  and 
characteristics  of  the  interbedded  shale.  An  operator  should  he  com¬ 
petent  to  pass  on  the  desirability  of  the  prospective  location  from  this 
point  of  view.  Wdiere  a  seam  is  not  essentially  horizontal  and  is  faulted, 
more  holes  might  be  necessary,  and  it  would  be  advantageous  to  the 
prospective  operator  to  have  an  ex])erienced  geologist  in  consultation 
to  advise  on  the  locations  of  holes  and  the  interpretation  of  the  struc- 


STRUCTURE  OF  HERRIX  COAL  NEAR  DUOUOIX 


;u 

ture  from  the  cores,  \\hth  careful,  thorough  work  it  would  be  pos¬ 
sible  to  locate  a  fault  where  the  throw  was  large  enough  to  be  a  very 
important  factor  in  mining; — that  is,  greater  than  10  or  15  feet. 
W  here  the  coal  seam  is  not  split,  and  the  strata  are  essentially  horizon¬ 
tal,  churn  drill  holes  would  probably  give  satisfactory  information  wiih 
regard  to  depth  and  continuity  of  the  coal  and  location  of  faults. 


I ! 


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»  ^  j  fc  •.  .-r  ^  *  - 


i  ?  - 


Downthrow  side  of  fault. 

Shipping  mine,  entrance  by  shaft. 
Shipping  mine,  entrance  by  slope. 


A. 


Strip  pit. 
Local. 
Abandoned. 
Drill  hole. 


Structure  contours  drawn  on  the 
base  of  the  Herrin  (No  6) 
coal  with  reference  to  sea  level. 

Certain. 


Doubtful. 


Problematical. 


LIST  OF 
(Active 

Map 

No.  Town 


1  Bois 


2  Tamaroa, 

3  Tamaroa. 

4  Sunfield. 

5  St.  John. 

6  St.  John. 

7  Duquoin . 

8  Duquoin. 

9  Duquoin . 

10  Duquoin. 

11  Duquoin. 

12  Duquoin. 


13  Dowell . 

14  Elkville . 

15  Hallidayboro. 

16  Ward . 

17  Ward . 

18  Hurst . 


19  Bush . 

20  Royalton .... 

21  Zeigler . 

22  Zeigler . 

23  Christopher. 

24  Christopher. 

25  Christopher. 

26  Valier . 

27  Sesser . 

28  Sesser . 


29  Weaver 


SHIPPING  MINES  IN  THE  AREA 
or  only  temporarily  idle  in  1923) 

Company 


Mine  No. 
or  Name 


WASHINGTON  COUNTY 
Kuhn  Colliery  Co . 


perry  county 

.Victory  Colliery  Co^ . 

Little  Muddy  Fuel  Co . 

.Bailey  Bros.  Coal  Co . 

.Gayle  Coal  Co . 

.Paradise  Coal  Co . 

Equitable  Coal  and  Coke  Co.. 

.Scott-Smith  Co . 

.Jewel  Coal  Co . 

.Jewel  Coal  Co — ;  ‘  ‘  h' ’/V  ’ 

.Rutledge  and  Taylor  Coal  Co 

JACKSON  COUNTY 

.Union  Colliery  Co.... . 

.  Black  Servant  Coal  Co . 

.Jackson  Coal  Co . . . 

..Midway  Coal  and  Mining  Co 

.  .Jackson  Peacock  Coal  Co . 

.  Bradbury-Scullion  Coal  Co... 


Diamond 

.  Strip  pit 
.  Paradise 
.Majestic 
.Strip  pit 

. No.  1 

. No.  2 

.  Security 


.  .Kathleen 
. .  Strip  pit 

. No.  1 

. No.  1 

Slope  mine 
Slope  mine 


FRANKLIN  COUNTY 


Western  Coal  and  Mining  Co... 

Franklin  County  Coal  Co . 

Bell  and  Zoller  Mining  Co . 

Bell  and  Zoller  Mining  Co . 

Old  Ben  Coal  Corporation . 

Old  Ben  Coal  Corporation . 

.Old  Ben  Coal  Corporation . 

.Valier  Coal  Co . 

Old  Ben  Coal  Corporation...... 

Southern  Gem  Coal  Corporation 


. No.  2 

.  .North  mine 
Zeigler,  No.  2 
Zeigler,  No.  1 

. No.  12 

. No.  10 

. No.  11 

. No.  1 

. No.  16 

. No.  2 


WILLIAMSON  COUNTY 
Old  Ben  Coal  Corporation 


No.  20 


H  * 


ILLINOIS  STATE  GEOLOGICAL  SURVEY 


REPORT  OF  INVESTIGATIONS.  NO.  5.  PLATE  1 


R.  2  W 


Sunflcld 


,SL 


OuQMln 


R  2W 


LEGEND. 


Boasduy  af  irwkatvb  H  «  r  r  i  o 
(No.  II  coal. 


Arvw  In  whlrk  tha  Itarrin  («tl 
bH  (>«*«  tvmoTCd  br  analen. 

Ar««i  of  tidit  Hatrla  cool  no* 
vorkobi*  under  irMint  eeo- 
nomk  rendtUon*.  o»  outUnod  Id 
min*  ooAlact. 

r*u)(,  wdatn. 

UoiTBIhio*  •U*  of  hulL 

Shipptai  mis*,  ntnse*  by  kluft. 

Shlpplnt  mlno,  entrance  b;  *lop*. 

Strip  pit. 

Local. 

Abandoned. 

UrlU  bole. 


SlfMctxira  contour*  dnan  on  lb* 
boM  of  the  n*mn  (No.  I) 
coal  with  reloranca  to  a*a  lerrt 

Certain. 


LIST  r 


SHIPPIXn  MIMtS  IV  TIIK  ARKA 


(  Arll<r  or  only  lemiunrllr  Ml*  In 
Tnwn  Compan.* 

t\  tSIlTVOTim  IWSTY 
Ini* . Kuhn  Oolllery  Co . 


1  Taniaioe.. 


IHufucIn.. 
I  Duqooln  . 
I  Uu'iuoln.. 


1  Doaell  . 

1  RIkMIl*  .  .. 

1  llalltdatbcro 


.  Ulamood 

...SIrtp  pit 

...|■an.ll*e 

. . .  Ua}**tlc 
Strip  I’ll 
N.i  I 


.  .Ketlilecn 

..mn^rii 


PKUHV  (  IIVNTY 

Vlrlcit)i  fvillery  CVj. . 

.  I.lllle  >l<t.Mr  fViel  Co.,.  .  .  .. 

Qalley  Droa.  Coal  Oo . 

,  0*,»I*  Coal  ib 
. .  WradI**  IVial  (V  .. 

Ktiullabl*  rv>*l  anil  O>lio  Co.. 

. -Uredl-Wtnllh  CV) . . 

.  Jeoel  (Val  <.to . 

.  J.*»l  (Vwil  tV(. .  .. 

.  Kulle-lc*  ami  Tavlor  Cool  IS. 

JACKSON  COltSTY 

.  Union  Colllrry  Co.  . 

llUek  ServanI  Coal  Co. . 

.TeeVann  Coal  Oo . 

Ui.lvrav  Coal  and  klinini  Oo..  ..,.pn  i 

IT  Wad  . Jack*on  Teewk  Coal  Oo .  Slo|-*  mine 

II  lluiel . llradlnir)  Scullion  Coel  CO . HIm|i*  mix* 

FRASKUS  COUNTY 

1(  Riitb . Uealrm  Coal  awl  Minlnd  Oo . No  9 

30  Koyallon...  Franklin  County  C-<nl  Oo .  .Nnrilimlnr 

91  /cl(Wir . Ilrll  alxl  Zulloi  Ulninc  Oo . X*l(l«r.  No  3 

3)  F.eleirr.  ...IIpII  ami  Kollrr  Ninlni  Oo . Relsler.  Nn  I 

31  Chrlal'.pher ,  .  OM  Urn  ('oil  CVeporallon  . 

34  dirlitopher  .  Old  lien  Coal  ('ntiniralinn . 

36  ChrUloptirr..  Old  lien  Cnal  ('orviirallon  — 

38  Valler . Valter  Ckul  Oi  . 

77  Sceeof . OU  Hen  Cioil  CorMrallon . 

38  Neeaer . Soulhem  Oeni  Coal  Coriwratlon,. 

WILLIAMSON  IXIUNTT 

7t  W'f'eT . Old  Hen  Coal  Corporallon . 


Map  of  tB«  Daquota  are*  sbowla^  favlts.  stncnire  et  the 


oi  ibe  Herrla  iNo  Cl  co*L  aad  diAtritanioo  oC  the  Herris  coal. 


-rf7.77 


A3AHaS  3V3I003030  3XVXS  STOMmr 


ILLINOIS  STATE  GEOLOGICAL  SURVEY 


REPORT  OF  INVESTIGATIONS  NO.  O,  PLATE  11 


structure  contourH  drawn 
on  tlio  baHc  of  Herrin 
(No.  fi)  COBl 

Certain 

Uncertain 

I’roblematical 

F'ault  (certain) 

Fault  (uncertain) 

liowntbrow  wide  of  fault 


Entry 
7§  \ir  shaft 
m  Hoist  shaft 


G-r 

-  J 


Map  of  Kathleen  mine,  Union  Colliery  Company,  showing  faults  and  structure  contours  on  Herrin  (No.  6)  coal,  secs.  4,  5,  and  8,  T.  7  S.,  R.  1  W. 


UNIVERSITY  OF  ILLINOIS-URBANA 


3  0112121903428 


